"a trajectory which would ultimately take him beyond the boundaries of Quakerism altogether"

"nothing represents the distance [George] Keith had travelled more than his critique of [his former collaborator Robert] Barclay’s Apology, published in 1702, in which the importance of outward forms was emphasized from the start. Therefore, he began by criticizing Barclay for supporting 'that Notion of other Quakers, to place the height of all Happiness in the true Knowledge of God, without the Knowledge of Jesus Christ, as the word Incarnate, or as he came in the Flesh, and was Crucified and dyed for our Sins'. In this way, Keith echoed the terms of his breach with Quakerism. Furthermore, he accused the Quakers of superimposing a metaphysical commitment against 'the Flesh' onto Christian doctrine. In a lengthy discussion of 2 Corinthians 5:16, cited by Barclay in discussion of his fifth and sixth propositions, Keith complained that the Quakers had co-opted Paul’s words to support their own mistaken understanding:

It is therefore a gross and strained sense, that the Quakers, and this Author of whom he had it put upon St Paul’s Words, After the Flesh, not referring to Christ’s Flesh in the Text, or to Christ as he came in the Flesh, but to that carnal and fleshly knowledge, that both St Paul and the Jews had of Christ …

Therefore, whilst Paul’s words were intended to stress the importance of a spiritual and living faith, Keith argued that the Quakers misused them to downplay the significance of the Incarnation. This led them to undervalue the importance of the outward Christ and rely solely on the Light within, rather than seeking guidance and support in the outward means of Scripture and the Church. In this way, Keith implied that the spiritualist Christology was intimately related to a spiritualist ecclesiology, and ultimately therefore a lack of true accountability in faith."

     Madeleine Pennington, Quakers, Christ, and the Enlightenment (Oxford:  Oxford University Press, 2021), 199-200.  That headline, from p. 198, isn't, in context, I think, entirely approving.  I can't tell for sure, but it seems to me that Pennington would have preferred a Keith who found a way to retain also what was theologically distinctive about Quakerism (e.g. its emphasis on "inward knowledge"), i.e. remain within its bounds.

"that man is void of judgment, and conscience, with respect unto God, that hath not a fact, and practice suitable thereunto"

"Then they demanded of me what the question was that I would dispute upon, whether I would dispute upon the things contained in my Sentence, and maintain my practice, for, said they, the Court Sentenced you not for your judgement or Conscience, but for matter of fact, and practice; to which I replyed, you say the Court condemned me for matter of fact, and practice; be it so, but I say that matter of fact and practice was but the manifestation of my judgment and conscience; and I make account that man is void of judgment, and conscience, with respect unto God, that hath not a fact, and practice suitable thereunto . . . [and] in truth, if the Faith and order which I profess do stand by the word of God, then the Faith and order which you profess must needs fall to the ground; and if the way you walk in remain, then the way that I walk in must vanish away, they cannot both stand together. . . ."

     The Baptist John Clarke to "the Honoured Court Assembled at Boston" in 1651, as reported in his Ill newes from New-England:  or A narrative of New-Englands persecution (London:  Henry Hills, 1652), 8.  Clarke of course—who had co-founded Rhode Island—refused the pejorative label Ana- or Rebaptist because he denied that infant baptism was any kind of valid baptism at all.
     I was put onto this by Hugh Barbour, The Quakers in Puritan England, Yale publications in religion 7 (New Haven and London:  Yale University Press, 1964), 214.